Jeremy Hunt has given the case of Nazanin Zaghari-Ratcliffe greater priority than his predecessor as Foreign Secretary, the imprisoned charity worker’s husband has said.

Richard Ratcliffe praised Mr Hunt for being “clear and critical” about his wife’s case, after she voluntarily returned to prison in Iran following an emotional family reunion over the weekend.

The British-Iranian mother was released from Evin prison in Tehran on Thursday and has been staying with family outside the capital.

However, the request for an extension was not granted and she was told she must return by sunset, her husband said.

Nazanin Zaghari-Ratcliffe with her husband Richard Ratcliffe and their daughter Gabriella (Family handout)

Mr Ratcliffe suggested there had been a change in the relationship with Iran since Mr Hunt replaced Boris Johnson as Foreign Secretary last month.

And he said he had “sensed a change in the way he has prioritised Nazanin’s case”.

“I think one of my complaints with the Government was that it didn’t feel like it was sort of treating her case with the public severity that I thought it deserved,” he told BBC Radio 4’s Today programme.

“He’s been great in that sense: he’s been clear and critical and he’s said ‘listen, she’s innocent and she shouldn’t be in prison, her treatment has been appalling’, and all the things that we’ve been asking the Government to do.”

Mr Ratcliffe added: “In terms of how the relationship with Iran has changed, well clearly she got out for a few days, that’s a pretty good sign and there have been some other improvements.”

On Sunday, Mr Hunt said he had spoken to Iran’s foreign minister Mohammad Javad Zarif on Friday but that it “clearly wasn’t enough”.

Looks like Iranian legal system is impervious to the simple fact at the heart of this: an innocent woman is desperate to be reunited with her family. Spoke to Foreign Minister Zarif on Fri but that clearly wasn’t enough. The fight goes on #FreeNazaninhttps://t.co/fknbIRC2lb

Vowing to continue the fight, he tweeted: “Looks like Iranian legal system is impervious to the simple fact at the heart of this: an innocent woman is desperate to be reunited with her family.”

Mr Ratcliffe, who told the programme he has been unable to get an Iranian visa, said his wife’s temporary release initially appeared to be a “very good sign”, but said it felt “pretty cruel at the end of it”.

He added: “It was a slight surprise that she was released but it felt consistent with positive noises, so it wasn’t just a bump, it was a proper brick wall yesterday that she was brought back in.”

Mrs Zaghari-Ratcliffe, from Hampstead, north London, was sentenced to five years in jail after being accused of spying by Tehran’s Islamist regime.

She denies the allegation and said she was on holiday in Iran to allow her daughter to spend time with relatives there.

Her four-year-old daughter Gabriella has been staying with family since Mrs Zaghari-Ratcliffe, who works for the Thomson Reuters Foundation, was detained at Imam Khomeini airport in April 2016.